Unilateral conductor for rectifying alternating currents



H. G. ANDRE Nov. 3, 1931.-

UNILATERAL CONDUCTOR FOR RECTIFYING ALTERNATING CURRENTS Filed. Oct. 17, 1928 Vii/V7042 rroxzwfcy Patented Nov. 3, 1931 mm a. man, or rams, FRANCE UNILATERAL CONDUCTOR FOR RECTIFYING ALTEBNATING CUBRENTS Application filed October 17, 1928, Serial No. 818,180, and in France October 26, 1927.

Experience of the different ways of achieving the rectifier, the object of my application No. S. 749,214, filed on November 11th, 1924, has shown that one of the conditions of ellicient o eration consists in the non-attackability of t 1e cathode by the liquid impregnating the space comprised between the electrodes.

The presence, notably of hydroxides upon the surface of the cathode is very pernicious.

It creates a zone of esca s for current and electrolysis which rapid y puts the rectifier out of use.

Observation reveals moreover that the setting in parallel of several rectifiers of this type is accompanied by bad commulation, the same as the addition of a static capacity at the terminals. Now, a single rectifier may be considered of which the cathode is partially altered as the reunion of several different apparatuses, in parallel.

In examining the cathode of such rectifiers it is observed that it is outside the colloidal anode that the attack acts, a fact which leads one to think that the presence of the anodal substance lessens the chemical attack, probably by the creation of a local couple.

The exterior portion to the anode from the cathode, combining with the radical acid 111 the case of the use of an acid as oxidizing agent, lowers its concentration, and electroly- SIS appears.

The present application has for its object a novel mechanical arrangement of the valve enabling the burying of the cathode in the anode, by protecting its outlet, and the creation of outlets for cathode and anode absolutely sealed, with a view to efiicient conservation of the rectifier.

It provides equally improvements of the chemical order with the same object.

According to the invention the valve is constituted by a tubeof silvered metal, doubled at the bottom by a silver cap which contains.

the known anodal material, made of colloidal silver soaked in sulphuric and phosphoric acids.

The cathode is composed of nickel, silicon, or a nickel silicon, or a nickel-silicon alloy as, for instance, a nickel-silicon alloy containing approximately 20-25% of silicon, or,

constituted b in general, any high corrosion-resisting metalhc composition, being fragile and little wearable is run over a stud of threaded iron or nickel, which enables a mechanical assembly in the perforated bottom of the metal tube. The cathode is of such a shape that its flat base is caused to reside against a joint, mica washers, which is rendered sealed y an impregnation under vacuum.

For this impregnation, the tube is placed upon a vacuum channel and the exterior of the joint is coated with anon-attackable substance such as bakelite varnish.

The apparent surface of. the cathode should be high y polished after moulding, which is to diminish its attackability.

The anodal powder which covers entirely the cathode has in this manner the advantage of not being moved after being placed into '70 position. It is then impregnated with liquid, then a bed of silica or glass sand is inserted. The closure is then terminated by magnetic washers, .then a glass tube, non-capillary which avoids the conductability of the liquid towards the outside. This tube is held by other washers residing on a cover soldered upon the metal tube.

The accompanying figure shows the new arrangement of the valve. The tube is silvered brass 1 contains a silver cap 2. which itself encloses the anodal powder 3. The cathode 4 is run over an iron stud 5 and is insulated by the mica washers 6, 6 These washers are pressed under a metallic washer 7 byterminal screw 8. The joint is impreg' nated by varnish at 9.

. Upon the silver is located silica 10 retained by the magnet washers 11, 11 and the glass tu e 12. The metal cap 13 maintains 93 the assembly.

In the silver powder is added a little copper or carbon or other metal of the same polarity which again minimizes the attack of the cathode by creation of a local couple. 95

Having now described and ascertained what is the nature of my invention and in what manner the same is to be performed, what I claim is:

1. An alternating current rectifier comprising an outer case, an anode of colloidal powder imbued with hyperconcentratcd -powder, imbued with hyperconcentrated acid, in close contact with a highly corrosion-resistant cathode, said cathode fixed upon a metallic rod havin a part pass-- ing throughout a hole-provided in a wall of said outer case, and joints-of insulation interposed between said cathode and said outer caseso astoffform' aflrobust and tight whole. '3. .dn ';alternating current rectifier comprising an outer case, an anode of colloidal powder j imbued with hyperconcentrated acid,; i n' 'close' contact wit-ha hi hl corrosion-resistant cathode, said catfio e being fixed upon ain'et alli'c' s tudboltl1aving a part passing throughout a' hole provided in a wall of said outer case, joints of insulation interposed between said cathode and said outer case,"'zind'a coating of an acid proof varnish, the whole being mounted in a rigid and robust manner".

4. An alternatingcurrent rectifier comprising an outer case, an anode of colloidal wder mixed wit-hoe per and imbued with y rcon'oentrated acid a iiglily corrosion resistant cathode,j said cathode beingfixed u on a metallic rod havin a part'passi'ng t 'roughout a hole provided in a wall of said outer case, joints of insulation interposed between said cathode and said'outer case, and a coating of an acid proof varnish, the whole being mounted in a rigid and robust manner.

5. An alternating current 'rectifier comprising an outer case, an anode of colloidal powder mixed with carbon and imbued with perconcentrated' acid, in close contact with a highly corrosion-resistant cathode, said cathode being fixed u n a metallic rod havin a partpassin tiroughout a hole provided in a wall 0 said outer case, joints of insulation interposed between said cathode and said outer case-, and a coating of an acid proof varnish, the wholebeing mounted in a rigid and robust manner.

6. An alternating current rectifier comprising,'in an outer case, an anode of colloidal powder mixed with copper and imbued with hyperconcentrated acid, in close contact with a highly corrosion-resistant polished cathode, said cathode being fixed upon a metallic stud-bolt'having a screwed part passing throughout a hole provided in a wall of said outer case, joints of insulation interposed between said cathode and said outer case, a nut screwed onthe screw of in close contact with means for tightly joining said cathode to an inner wall of said outer casing.

HENRI G, ANDRE. 

